Not sure. Yesterday, both before and after the FAA grounded them, FlightAware showed a lot of Canadian B38Ms flying through the ADIZ, either from Mexico heading up to Canada, flying in Canadian airspace to land at various airports, and a couple of SWA flights still in the air. None were diverted.

tyketto tracked those still in the air, heard no related audio that I was able to look for. but those that were in the air, were still allowed to get to their final filed destinations.

Under the emergency order, all Boeing 787 Max 8 that are already in the air will be grounded after arriving at their destinations. John

However, it doesn't explain the WJA and SWG flights, as Canada had already banned and grounded them a day before the US did, and the WJA and SWG flights were still operated. They were revenue-based flights and not anything for repositioning, so there isn't any real explanation for why they still flew the day after. Regardless, they all landed safely, so nothing is out of the ordinary.